The objective of this project is to evaluate which wooden stick structure will hold more weight.

1. Please remember that load testing may result in the destruction of the structure! We won’t know what the maximum load your structural model can hold until it breaks.

2. Decoration and painting are allowed, but the judge (me and probable two other colleagues) will decide if any additions (other than those made from the given material) result in an unfair advantage to a structure entered for load testing.

3. Be creative and have fun!

Grading

> 95

94-80

79-65

<65

Held the maximum load

0.9·Fmax

0.8·Fmax

<0.7·Fmax

Non-truss design

Classical truss

-

Simply supported beam

Spans 1.60 m ± 10cmable to rest on supports

Longer by more than 5cm

Shorter between 5 to 15 cm

Shorter by more than 15 cm

Materials used <70%

70%-80%

80%-90%

90%-100%

Aesthetically pleasing

Somewhat

Not

Not

Decorated

Not decorated

-

-

Plans

Not complete

With mistakes

None

On task 100%

2 warnings

3-4 warnings

>4 warnings

The width of the wooden stick model: between 25 cm and 40 cm. Not more, not less!

All the teams must submit also a DESIGN PROJECT. What to include in the plans:

1. The dimensions of the sticks - length and width in [cm] 2. Number of sticks needed to span 1.60 m ± 10 cm3. A drawing of what the structural model will look like with measurements. 4. The estimated ultimate load

ONLY the structural model designs that conforms to the specifications below will be accepted for stress load testing.

1. The structural models must be constructed only of the given materials (wooden sticks, ropes and nails).

2. Water-soluble glue such "Aracet" is allowed. No Epoxy or resin based glue may be used.

3. The sticks may be cut and/or shaped in any way, but only the provided water-soluble glue may be used to join them.

4. No nails, screws or fasteners of any kind, made from any material, wood included, may be used unless they are fashioned by the designer/builder from his/her received sticks.

5. Composed members by two or more sticks stacked together are not allowed.

6. The stick structural model must span a clear space between 150 cm to 170 cm.

7. The model must accept the "test load block" (described below) in the center of the span on the upper side of the structure.

8. The test load block is estimated to be of about 50 to 60 cm long, 50 cm wide, and a height of at least 70 cm. The test load will be applied through this load block which will be simply supported on the upper side of the structure. The loading span of the test block will be between 30 cm and 50 cm (no longer, no shorter!). The builder clearly specify in the project the span of the test load (between the concentrated forces transmitted).

9. A stick structural model will be considered to have "failed" under the test load if any of the following conditions occur:

any stick structural model member breaks, fractures, cracks or separates from any attachment or joint, resulting in the collapse of the structure (ie: the model breaks and falls down);

the lower side deforms downward sufficiently to allow the test load suspended below the stick model to touch the floor;

the structure tips, bends, falls, or otherwise fails to remain on the load testing apparatus when solely under the stress of the test load.

10. Load testing will consist of the application of increasing weight loads via the test load block until a failure under Rule 9 occurs.

11. If two identical structures will fail at the same load, the lighter wooden stick model will won.

12. Each team will receive (after the Easter holiday, on May 4th):

- 4 wooden pine sticks of 10 mm x 10 mm x 2000 mm;

- 12 wooden pine sticks of 10 mm x 10 mm x 1000 mm;

- 3 wooden pine sticks of 5 mm x 20 mm x 1000 mm.

13. The following common tools are available, and the teams must use them in appropriate conditions:

- 1 drilling machine;

- 2 screw taps of 3 mm diameter;

- 2 screw taps of 4 mm diameter;

- 1 kg of water-soluble glue type Aracet;

- 2 special hand saws with 12 blades for wood.

All the tools must be used ONLY for wooden materials. Please, do not use them for metal or concrete!

14. All the above tools must be returned functional, and in good conditions after the contest.

15. All the remained materials (wooden sticks) must be also returned. The grade score will be considered ONLY if the material economy is proved to be a real one. The very small fragments will not be considered.